Australian Patent No 558476 discloses a method of producing a plastics bank note or security token or the like comprising a transparent polymeric substrate coated with layers of opaque material applied in such a way as to leave a transparent area which may include an optically variable security device, such as a diffraction grating, on an opaque, reflective layer of foil.
Whilst plastics bank notes with transparent areas including diffraction gratings as optically variable security devices, such as disclosed in Australian Patent No 558476, are difficult to reproduce, in low value plastics bank notes the process of incorporating diffraction gratings in the notes may be too costly or not felt to be needed.
It is therefore desirable to provide a bank note or other security document or token with a simpler, less expensive security device but which is still effective and difficult to reproduce.
It is also desirable to provide a method of, and apparatus for, producing bank notes or other security documents or tokens with low cost security devices that are difficult to reproduce.
It is further desirable to provide a plastics bank note or other security document or token with a security device that produces an optically variable effect when the note, document or token is rotated or viewed from different angles and which gives feel or texture to the note, document or token.